NEW YORK (CBSNewYork) — As police, family and volunteers searched for a sixth day Wednesday for a missing 14-year-old autistic boy, the teen’s relatives took the first step toward filing a lawsuit, alleging his Queens school did not do enough to prevent him from running off campus.

Meanwhile, a $5,000 reward has been offered by a local law firm for his safe return.

Avonte Oquendo has been missing since Friday. He was last seen on school surveillance video leaving the Center Boulevard School in Long Island City.

Avonte Oquendo has been missing since Oct. 4, 2013. (credit: Handout)

Since Oquendo vanished, police and other searchers have taken to subways and trains in all five boroughs, hoping that someone might have seen him.

Oquendo cannot verbally communicate and has a fascination with trains. Thus, the search has focused on the mass transit system.

The Oquendo family filed a claim Wednesday to sue the city and school district for failing to properly supervise Oquendo, CBS 2’s Tracee Carrasco reported.

“The child’s grandmother spoke to a security guard when she came to the school several hours later,” said the family’s attorney, David Perecman. “And the security guard told her that the child was leaving school, and she said, ‘Where are you going?’ He doesn’t speak. And the child said nothing. And she let him leave.”

Perecman also said it took the school too long to notify the boy’s mother about his disapperance.

“The school had ordered a lockdown and was looking for the child in the school for an hour before they even let Mom know,” he said.

On Tuesday, police thought they found Avonte in East Harlem. The teen’s older brother, Daniel Oquendo, and several others involved in the search were told by police he had been found alive at 123rd Street and Lexington Avenue.